Plasma processing apparatus and plasma processing method

Abstract

Provided is a plasma processing apparatus which comprises a chamber, a stage configured to set a holding sheet and a substrate held thereon, a securing mechanism configured to secure the holding sheet on the stage, a plasma generator including a first electrode and a first high-frequency power supply, and a determiner for determining a contact status between the holding sheet and the stage, wherein a gas through-hole is arranged on a surface of the stage in an annular region defined between an inner edge of a frame set on the stage and an outer edge of the substrate, and wherein the determiner is configured to determine the contact status in accordance with a pressure of a gas in the gas introduction conduit and/or a regulation data for regulating the pressure of the gas, the gas being introduced between the stage and the holding sheet from the gas through-hole.

What is claimed is: 
     
       1. A plasma processing apparatus, comprising:
 a chamber: 
 a stage provided inside the chamber and configured to set a holding sheet and a substrate held thereon, the holding sheet having a circumference secured on a frame; 
 a securing mechanism configured to secure the holding sheet on the stage; 
 a plasma generator including a first electrode and a first high-frequency power supply for supplying a high-frequency power to the first electrode; and 
 a determiner for determining a contact status between the holding sheet and the stage; 
 wherein a gas through-hole connected to a gas introduction conduit is arranged on a surface of the stage in an annular region defined between an inner edge of the frame set on the stage and an outer edge of the substrate, and 
 wherein the determiner is configured to determine the contact status in accordance with at least one of a pressure of a gas in the gas introduction conduit and a regulation data for regulating the pressure of the gas in the gas introduction conduit, the gas being introduced between the stage and the holding sheet from the gas through-hole through the gas introduction conduit. 
 
     
     
       2. The plasma processing apparatus according to  claim 1 , wherein the gas through-hole is arranged closer to the outer edge of the substrate than the inner edge of the frame in the annular region. 
     
     
       3. The plasma processing apparatus according to  claim 1 ,
 wherein the securing mechanism is an electrostatic chucking mechanism provided in the stage, and includes a pair of semi-circular electrodes, and 
 wherein each of the semi-circular electrodes has an arc portion arranged between the outer edge of the frame set on the stage and the outer edge of the substrate, and a first window arranged at a position corresponding to the gas through-hole. 
 
     
     
       4. The plasma processing apparatus according to  claim 1 , further comprising:
 a bias-potential generator including a second electrode provided in the stage and a second high-frequency power supply for supplying a high-frequency power to the second electrode, 
 wherein the second electrode has an outer edge arranged between the outer edge of the frame set on the stage and the outer edge of the substrate, and a second window arranged at a position corresponding to the gas through-hole. 
 
     
     
       5. A plasma processing method, comprising:
 a setting step for setting a holding sheet on a stage provided in a plasma processing apparatus, the holding sheet having a circumference secured on a frame; 
 a securing step for securing the holding sheet on the stage; 
 a determining step for determining a contact status between the holding sheet and the stage; and 
 a plasma etching step for etching the substrate on the stage by exposing a surface of the substrate to a plasma atmosphere upon determining the contact status as being acceptable, 
 wherein a gas through-hole connected to a gas introduction conduit is arranged on a surface of the stage in an annular region defined between an inner edge of the frame set on the stage and an outer edge of the substrate, and 
 wherein in the determining step, a gas is introduced between the stage and the holding sheet from the gas through-hole through the gas introduction conduit, and the contact status is determined in accordance with at least one of a pressure of the gas in the gas introduction conduit and a regulation data for regulating the pressure of the gas in the gas introduction conduit. 
 
     
     
       6. The plasma processing method according to  claim 5 , wherein the gas through-hole is arranged closer to the outer edge of the substrate than the inner edge of the frame in the annular region. 
     
     
       7. The plasma processing method according to  claim 5 ,
 wherein a pair of semi-circular electrodes are provided in the stage, each of the semi-circular electrodes having an arc portion arranged between the outer edge of the frame set on the stage and the outer edge of the substrate, and a first window arranged at a position corresponding to the gas through-hole, and 
 wherein in the securing step, the holding sheet is secured on the stage by applying the semi-circular electrodes with a potential for generating a sticking force between the holding sheet and the stage. 
 
     
     
       8. The plasma processing method according to  claim 5 ,
 wherein a second electrode is provided in the stage, and 
 wherein the second electrode has an outer edge arranged between the outer edge of the frame set on the stage and the outer edge of the substrate, and a second window arranged at a position corresponding to the gas through-hole.